The spokesman said the airline maintained high standards, including hygiene conditions, adding that this was a “very rare incident.”

The loss-making airline has been hit by a string of issues, including over safety. In May, a flight to Bangalore was diverted to another city after the pilot returned from a toilet break and found the door to the cockpit jammed shut.

Air India also this year suspended a senior pilot caught drunk just before he was to fly a passenger aircraft.

Air India is the country’s fourth-largest airline by market share, and has been hit hard by rising fuel prices and fierce competition from private carriers that have added to a legacy of labour problems and crushing debts.